Outlet box extension



June 19, 1945. H. PEEVEY 2,373,861

OUTLET BOX EXTENSION Filed April 20, 1944 2 Sheets-Sheet 1 Inventor 'LAFAYETTE H. PVY,

y new Jun 19, 1945. H P EVEY 2,378,861

OUTLET BOX EXTENSION Filed April 20, 1944 2 Sheets-Sheet 2 Inventor 4 Z A LAFAYETTE HPEEVEY,

Patented June 19, 1945 UNITED STATES PATENT OFFICE OUTLET BOX EXTENSION I Lafayette H. Peevey, Alameda, Calif.

Application April 20, 1944, Serial No. 531,934

3 Claims.

This invention relates to outlet or junction boxes such as are used in electrical house wiring systems, and has more particular reference to an extension for said boxes whereby the depth of the latter may be increased when found necessary.

After outlet boxes are installed in buildings during construction of the latter, it is sometimes found necessary to apply furring and plaster to the wall surface so that the box is no longer flush with the outer surface of the wall, but is located inwardly of said outer surface. In such an event, it is necessary to perform additional difficult work in order to overcome the undesirable condition that exists. Also, in the erection of concrete structures it is necessary to cut the concrete form so that the outlet box will project when the form is removed and so that the box will be flush with the surface when the plaster is applied to the surface of the wall.

The primary object of the present invention, therefore, is to provide an extension for outlet boxes whereby the above-mentioned difflculties and objections are overcome. In the cases where additional furring and plastering is applied to the surface of the wall after installation of the outlet box, the present extension can be adjusted flush with the added surface layer without disturbing the original installation of the box. In the other event, the extension may be adjusted inwardly so that it will be flush with the concrete wall being constructed and so that it will merely contact the form instead of projecting into a cut out formed therein. After the form is removed, the extension can be extended so that it will lie flush with the plaster applied to the surface of the wall, In this way, considerable difilculty and expense is avoided, but an outlet box construction is presented which is satisfactory and meets with all legal requirements.

A specific object of thepresent invention is to provide an outlet box extension of the above kind which is simple in construction, easy to use and economical to manufacture.

Another object of the present invention is to provide means whereby the depth of the outlet box extension may be readily decreased for adapting the same for use in connection with outlet boxes which are shallower than the extension, particularly when it is only necessary to increase the effective depth of the outlet box a slight amount by the use of the present extension.

Other objects and features of the present invention will become apparent from the following description when considered in connection with the accompanying drawings, and the invention consists in the novel form, combination and arrangement of parts hereinafter more fully described, shown in the drawings and claimed.

In the drawings, wherein like reference characters indicate corresponding parts throughout the several views:

Figure 1 is a developed perspective view illustrating the parts of the present extension and a conventional outlet box in separated relation.

Figure 2 is a sectional view through an outlet box equipped with the present extension and taken substantially on the plane of line 2-2 of Figure 3.

Figure 3 is a view in section and taken substantially on the plane of line 3-3 of Figure 2.

Figure 4 is an enlarged fragmentary detail section taken on line 4-4 of Figure 2.

Figure 5 is an elevational view looking toward the right of Figure 4.

Figure 6 is a section through one wall of the extension on line 66 of Figure 1, and drawn on an enlarged scale.

Referring in detail to the drawings, 5 indicates a conventional outlet box which is of a permanent size and comprises integral side, end and bottom walls, and is open at the top or front. The end walls are formed with the usual openings 6 to facilitate coupling of conduits l to the box, as at 8, whereby the wires in said conduits may be extended into the box near the back or bottom wall thereof. At the open front of the box 5, the end walls are provided with central inwardly projecting lugs 9 having threaded apertures ID that usually receive screws by means of which a fixture is secured in position within the box and with its outer face flush with the open front of the box.

The present invention contemplates the provision of an extension for a conventional outlet box such as described above, whereby the effective depth of said box may be increased when desired, As shown, this extension includes a tubular body ll corresponding in shape to that of the box 5, but of slightly smaller size "than the latter, so that said extension body II will snugly telescope into the box 5 through the open front thereof. At its open front end, the body H is provided with central inwardly projecting lugs 9a similar to the lugs 9 and provided with suitable openings Illa larger than the openings ill. Also, the body H is provided with central elongated slots l2 in the end walls thereof that extend part way of the depth of the body II and open through the inner or rear edges of the end walls. The slots are of a width slightly greater than that of the lugs 9 so that the latter will be received in said slots when the body II is telescoped into the box 5. Special screws 13 are provided for connecting the extension body H with ll adapted to screw into the openings It of the lugs i. The openings I to are formed so that the heads ll of, the screws It \will have a countersunk position therein. Also, the heads II are provided with screw driver kerfs it to facilitate turning of the same. Obviously, by turning the screws I! in one direction, the extension body ii may be adjusted inwardly with respect to the box 5, while turning of the screws II in the opposite direction will effect outward adjustment of the extension body with respect to the box I. The larger ends of the screws I! are provided with axial threaded sockets H for reception of ordinary attaching screws it by means of which a receptacle, or fixture, indicated at is by dotted lines, may be secured in place within the extension body, and in a well known manner.

To illustrate the utility of the present extension, reference may be had to Figure 8 wherein it indicates a wall whose normal surface was at it and within which is set the outlet box with its open end fiush with said surface 2|. ing that an additional surface layer 22, of p astic, has been found necessary for application to the surface 2! after installation of the box 5, it will be evident that the open front of the box 5 will then be located inwardly of the new outer surface 23 of the wall. In order to overcome this diiilculty without disturbing the installation of the box 5, the present extension is employed by sliding the body ii into the box 5 and adjusting it relative to the latter so that the outer open end of the body H is located fiush with the new surface 23 of the wall. This adjustment is effected by turning the screws 58, and such screws will retain the adjustment. The fixture it may then be readily secured in proper position within the extension box it by means of the screws id threaded into the sockets ll of screws I8, as illustrated in Figure 4.

Where extremely shallow outlet boxes are employed, it may be necessary to decrease the depth of the extension body ii, and in order to facilitate this, the rear end portion of the body in is provided with readily removable sections 2d that are made readily removable by weakening or scoring the body ii along spaced parallel lines,asat 25, and along lines parallel with the free edges of the walls of said body i i. Also, in that event, or when only a very slight extension of the conventional box is required, the depth of the slots 02 may be increased by providing the end walls of the body H with readily removable sections 26 coincident with the inner ends of and of the same length as the width of said slots i 2. These sectiofis 26 may be made readily removable by scoring the end walls of the body il, as at at.

It will be apparent that in erecting concrete walls, the box 5 may be set with its open front flush with the surface 2i rather than projecting outwardly of said surface as usual. Obviously, when the box 5 is set to project outwardly of the surface 2i, it is necessary to cut the concrete form for reception of the projecting portion of the box. The present extension eliminates this necessity because the extension can be applied after the wall 20 is completed and before the surface layer 22 is applied, the extension then being adjusted so as to have its outer portion flush with the new surface 23 that will be presented.

From the foregoing description, it is believed that the construction and manner of use. as well as the advantages of the presentinvention, will be readily understood and appreciated by those skilled in the art. Minor changes may be made in details of construction illustrated and described, such as fall within the spirit and scope of the invention as claimed.

What I claim is:

1. In combination with a conventional electric outlet box of predetermined permanent size and wherein the outlet box has an open front and central inwardly projecting lugs located on v the front of the end walls of the box and pro vided with threaded openings, an adjustable extension ior variably increasing theeiiective depth of said box and comprising a tubular body of a size and shape to snugly 'slidably telescope into said box and provided at the front of its end walls with central inwardly projecting apertured lugs. said end walls of the body having central slots therein open at the rear of the body and adapted to slidably receive the lugs of the box, and screws passing through the lugs of the body and threaded into the lugs oi the box for adjusting the body inwardly or outwardly relative to the box.

2. An adjustable extension for variably increasing the effective depth of a conventional electric outlet box of predetermined permanent size and wherein the outlet box has an open front and central inwardly projecting lugs located on the front of the end walls of the box and provided with threaded openings, said extension comprising a tubular body of a. size and shape to snugly slidably telescope into said box and provided at the front of its end walls with central inwardly projecting apertured lugs, said end walls of the body having central slots therein open at the rear of the body and adapted to slidably receive the lugs of the box, and screws passing through the lugs of the body and adapted to be threaded into the lugs of the box for adjusting the body inwardly or outwardly relative to the.

box, the inner portion of the body being scored along parallel lines parallel with the rear edges of the walls of the body and providing the latter with readily removable sections adapted to be removed to selectively decrease the eflective depth of the body. I

3. In combination with a conventional open front electric outlet box provided on the front of its end walls with central inwardly projected lugs having threaded openings, an adjustable extension for variably increasing the eflective depth of said outlet box, comprising a tubular body of a size and shape to snugly slidably telescope into said outlet box and provided at the front of its end walls with central inwardly projecting aperturedlugs, said end walls of the body having central slots therein terminating short of the outer end of the body and open at the inner end of the body and slidably receiving the lugs of the box, and screws passing through the lugs of the body and threaded into the lugs of the box for adjusting the body inwardly or outwardly relative to the box, the end walls of the body being scored along parallel lines at the outer ends of said slots to provide readily removable end wall sections at the outer ends of and corresponding in width to that of the slots, said sections being removable to increase the depth of the slots.

LAFAYETTE I-I. PElilVEY. 

